lec on advanced designs Flashcards
what does “two” mean in two way designs?
we are going to vary things in at least two ways. it can be things we control or measure.
interaction effects occur when…
the effect of one IV depends on the level of another IV
definition of interaction effect
the difference of differences
experiments with __ IV(s) can show interactions
2
factorial designs study __ IV(s)
2 (or more)
factorial designs can:
test limits
test theories
show us main effects and interactions
cross over interaction
“it depends”
lines on graph cross over eachother
terminating or spreading interaction
“especially when”
lines do not cross , might run parallel to eachother
IVs are also called…
factors
factorial designs can be used to study what 2 types of variables?
manipulated variables
participant variables
in factorial designs, participant variables are treated as ___
IVs
what is an example of a participant variable
age, as they cant assign people to be old or young so its just a participant variable
if there are 2 IVs with 2 levels in each, how many cells or conditions are there
4 (2 levels of IV1 x 2 levels of IV2)
factorial designs testing limits is important for what type of validity?
external validity
using factorial designs to test limits is also called ________ ____ _______
testing for moderators
whats a moderator
IV that changes the relationship between another IV and DV
it results in an interaction
the effect of one IV is moderated by the level of another IV
what type of question do you ask when interpreting if there is a main effect?
is there an overall difference?
what type of question do you ask when interpreting if there is an interaction effect?
is there a difference in differences?
what is more important, main effects or interactions
interactions
when analyzing a factorial study with 2 IVs there are 3 results to interpret. what are they?
2 main effects
1 interaction effect
list the factorial variations
- independent groups factorial designs
- within groups factorial designs
- mixed factorial designs
- increasing the number of levels of an independent variable
- increasing the number of independent variables
independent groups factorial designs
both IVs are studied as independent groups and both IVs are manipulated BETWEEN groups
what are independent groups factorial designs also called
between subjects factorial design
within groups factorial designs
both IVs are manipulated WITHIN groups
what are within groups factorial designs also called
repeated measures factorial designs
in what way are within group designs the most efficient? explain
most efficient in terms of number of participants needed.
if you have a 2x2 within group design, there is only 1 group of participants but they participate in all 4 cells
ex: if u want 50 ppl in each cell u only need 50 ppl total because each of them would be in each of the 4 conditions
increasing number of levels of an IV
changes the number of cells (increases it)
how are factorials (factors) notated? what does it mean?
____x_____
number of blanks tells u the number of IVs and numbers that you put in the blanks tell you the number of levels of each of the IVs
ex; 12 cells = 3x4 factorial design
how are interactions most easily detected?
with a line graph, see if the lines are parallel.
what is the best way to represent a design with increased number of IVs (like a 3 way design)
make the 2x2 table twice, once for each level of IV3
